Ontogenetic pattern,morphological sexual and side dimorphism in the saccular otolith of a scaleless killifish Aphanius furcatus (Teleostei: Aphaniidae)

The relationships between ontogenetic and sexual factors with otolith morphology are poorly studied in killifish genus Aphanius Nardo, 1827. We studied the ontogeny, morphological sexual and side dimorphism in the saccular otolith of a scaleless killifish Aphanius furcatus inhabiting a high‐salinity environment in Southern Iran. The results highlighted growth‐dependent variability in the otolith of A. furcatus, which might be useful to define its certain developmental stages. We underlined those characters that were consistent during fish development, which could be valuable to identify the species. Considering the ontogenetic pattern of otolith in A. furcatus, it was found that the otoliths of young individuals have largely been influenced by sexes and that it was reduced during the fish development. Morphological side dimorphism in the otolith of A. furcatus tends to be increased during fish development. The outcomes of this study are essential since they have provided new information on ontogenetic changes and the sexual and side dimorphism of Aphanius otolith.